I have used screen protectors for three iPhones and an iPod Touch, but this protector on my new 4S is the best one I have had. The matte finish is glare free, and, more importantly, doesn't show finger marks! I actually like the feel of the matte finish better than the original glass. To install it properly, you should look at a YouTube video that explains how to remove bubbles. Dust specks are pretty inevitable, but, if you use tape to remove them, you can get a perfect installation!
Shortly after purchasing the product, I received an e-mail from Callum, the founder of PhoneDevil/MediaDevil, thanking me for my purchase, providing a link to a very useful YouTube installation video, and encouraging me to contact him with comments, good or bad. I contacted him regarding a specific issue I had, and got an immediate response. I didn't realize that the iPhone 4S has a small raised lip around the outside of the glass. Because my initial installation started slightly too high, I couldn't get the top of the protector to stick to the glass. Callum's prompt e-mail response suggested that the protector was perched on the small lip which prevented it from contacting the screen.....he was absolutely correct! One other advantage of this protector is that you can remove it and replace it. With other screen protectors I have used, once you peel it back from the screen, it will never stick again. The final installation is absolutely perfect and bubble-free. I highly recommend this excellent product and wish other suppliers provided the same level of customer support.